The Collaborative International Dictionary of English v.0.48:

Condiment \Con"di*ment\, n. [L. condimentum, fr. condire. See
   Condite.]
   Something used to give relish to food, and to gratify the
   taste; a pungment and appetizing substance, as pepper or
   mustard; seasoning.
   [1913 Webster]

         As for radish and the like, they are for condiments,
         and not for nourishment.                 --Bacon.
   [1913 Webster]

WordNet (r) 3.0 (2006):

condiment
    n 1: a preparation (a sauce or relish or spice) to enhance
         flavor or enjoyment; "mustard and ketchup are condiments"

Moby Thesaurus II by Grady Ward, 1.0:

99 Moby Thesaurus words for "condiment":
   Tabasco, Worcestershire sauce, allspice, anchovies, angelica,
   applesauce, basil, bell pepper, black pepper, borage, burnet,
   caper, capsicum, caraway seeds, cardamom, catsup, celery salt,
   chervil, chili, chili sauce, chili vinegar, chives, chutney,
   cinnamon, cloves, condiments, coriander, cranberry sauce, cubeb,
   cumin, curry, dahl sauce, dill, dillseed, duck sauce, fagara,
   fennel, file, five spice powder, flavor, flavorer, flavoring,
   garlic, garlic butter, garlic powder, garlic salt, ginger,
   green pepper, hedge garlic, horseradish, hyssop, leek, mace,
   marinade, marjoram, mayonnaise, mint, mustard, nutmeg, onion,
   onion salt, oregano, paprika, parsley, pepper, peppercorn,
   peppermint, piccalilli, pickle, pimento, pimpernel, potherb,
   radish, red pepper, relish, saffron, sage, salad dressing, salt,
   sauce-alone, savory, seasoned salt, seasoner, seasoning,
   sesame oil, sesame seeds, shallot, soy, soy sauce, spice,
   star anise, tarragon, tartar sauce, thyme, tomato paste, turmeric,
   vanilla, vinegar, white pepper